A string inverter control method includes: in a process of performing IV curve scanning on one or more first direct current/direct current step-up circuits, controlling a change of an output voltage of one or more second direct current/direct current step-up circuits on which the IV curve scanning does not need to be performed, where a change trend of the output voltage and a change trend of an input voltage of the one or more first direct current/direct current step-up circuits on which the IV curve scanning is performed present a non-strictly monotonically increasing relationship. Therefore, for the direct current/direct current step-up circuit on which the IV curve scanning is performed, a voltage difference between two ends of the direct current/direct current step-up circuit is not always in a relatively high state, so that a ripple current on an input inductor in the direct current/direct current step-up circuit can be reduced.

A string inverter control method includes: in a process of performing IV curve scanning on one or more first direct current/direct current step-up circuits, controlling a change of an output voltage of one or more second direct current/direct current step-up circuits on which the IV curve scanning does not need to be performed, where a change trend of the output voltage and a change trend of an input voltage of the one or more first direct current/direct current step-up circuits on which the IV curve scanning is performed present a non-strictly monotonically increasing relationship. Therefore, for the direct current/direct current step-up circuit on which the IV curve scanning is performed, a voltage difference between two ends of the direct current/direct current step-up circuit is not always in a relatively high state, so that a ripple current on an input inductor in the direct current/direct current step-up circuit can be reduced.

The present invention relates to an optimizer, for a solar string power generation system, comprising an Injection Circuit (IC), connected to at least one string, from an array of strings of solar panels, wherein the output of said IC is connected to the DC bus of the solar inverter. The IC comprises: (i) an MPPT mechanism, for finding the MPP of the connected string; (ii) a DC/DC converter, for converting part of the power of said connected string; wherein the DC/DC converter, converts only a part of the power of the string, that is connected to the IC, when the string is impaired, for compensating for the relative voltage difference between the voltage MPP, of the impaired string, and the MPP voltage of the DC bus of the solar inverter and the array of strings.

The present invention relates to an optimizer, for a solar string power generation system, comprising an Injection Circuit (IC), connected to at least one string, from an array of strings of solar panels, wherein the output of said IC is connected to the DC bus of the solar inverter. The IC comprises: (i) an MPPT mechanism, for finding the MPP of the connected string; (ii) a DC/DC converter, for converting part of the power of said connected string; wherein the DC/DC converter, converts only a part of the power of the string, that is connected to the IC, when the string is impaired, for compensating for the relative voltage difference between the voltage MPP, of the impaired string, and the MPP voltage of the DC bus of the solar inverter and the array of strings.

A PV-optimiser power system for a photovoltaic installation for supply of power from a photovoltaic installation. The system includes a first DC/DC converter connected to a PV panel and to one or more energy storage modules, and a second DC/DC converter, connected in parallel to the PV panel in a string of PV panels of a PV installation, wherein the second DC/DC converter is configured to operate as an optimiser and execute a maximum power point tracking algorithm (MPPT) to determine the maximum power output of the PV panel of the plurality of the PV panels in the string.

A modular power supply apparatus for use in harsh climates that comprises a portable, low cost, easily maintained, durable power supply for energy production as well as systems, methods for forming, and methods of using same.

A modular power supply apparatus for use in harsh climates that comprises a portable, low cost, easily maintained, durable power supply for energy production as well as systems, methods for forming, and methods of using same.

Systems, apparatuses, and methods are described for discharging an input voltage by utilizing discharge circuitry configured to produce a relatively constant discharge voltage value/output voltage, a relatively constant discharge current value/output current, or a relatively constant discharge power value/output power. The discharge circuitry may include at least one power device, such as a DC to DC converter.

Systems, apparatuses, and methods are described for discharging an input voltage by utilizing discharge circuitry configured to produce a relatively constant discharge voltage value/output voltage, a relatively constant discharge current value/output current, or a relatively constant discharge power value/output power. The discharge circuitry may include at least one power device, such as a DC to DC converter.

A three-phase grid-connected inverter, and a method and a device for controlling the three-phase grid-connected inverter are provided. The method is applied to a three-phase three-leg grid-connected inverter. A structure of the three-phase three-leg grid-connected inverter is improved, so that a filter capacitor (C1, C2, and C3) is connected to a negative electrode of a direct current input bus to form a harmonic bypass circuit. Inverter devices connected in parallel in the system operate stably without increase of inductance of an inductor (L1, L2, L3). In addition, the three-phase three-leg grid-connected inverter according to the present disclosure operates in a discontinuous mode of inductor current (i.sub.L1, i.sub.L2, and i.sub.L3). That is, in the process that a power switch transistor (Q.sub.1, Q.sub.2, Q.sub.3, Q.sub.4, Q.sub.5 and Q.sub.6) on bridge legs is turned on, the inductor current (i.sub.L1, i.sub.L2, and i.sub.L3) drops to zero.